<!doctype html>
No crash = pass
<br>
Ridiculous markup is needed, empirically, to trigger a race condition.
<div id=test style="display: table-footer-group"></div>
<script>
  if (window.testRunner) {
    testRunner.waitUntilDone();
    testRunner.dumpAsText();
  }
  var testElement = document.getElementById('test');
  document.addEventListener("keydown", function() {
    testElement.requestFullscreen();
  });
  document.addEventListener("fullscreenchange", function() {
    if (window.testRunner)
      testRunner.notifyDone();
  });
  eventSender.keyDown("Enter");
</script>
</body><style>
* { writing-mode: vertical-rl;</style><style>
</style><style>
</style><style>
</style><style>
</style><style>
</style><style>
</style><style>
</style><style>
</style><style>
</style><style>
</style><style>
.c26::-webkit-media-controls-timeline-container { speak: spell-out; margin-width: auto; fill-rule: evenodd;</style><style>
 animation-fill-mode: both, backwards; margin-bottom: 1.32195719389cm;  }</style><style>
 grid-columns: auto 23fr; grid-gap: 7px 6px 128px;  }</style><style>
</style><style>
</style><style>
 text-decoration-line: overline; border-width-bottom: 32551px; border-style: dashed dotted solid; box-shadow: crimson 11 32579 7px;  }</style><style>
</style><style>
</style><style>
</style><style>
</style><style>
</style><style>
</style><style>
</style><script>
